Chef's Choice M112 3-Stage Ultra Hone Sharpener - Black I've knives a razor sharp finish with this professional 3-Stage Diamond Ultra Hone knife sharpener that incorporates advanced technology to quickly and easily sharpen both fine edge and serrated 20 degree class knives^Better than factory sharpness with this 3-Stage sharpener with precision angle control^100% diamond abrasives in Stages 1, 2 and 3^Fast, foolproof results^Engineered and assembled in U.S.A.